(2007) µThe early anthropogenic hypothesis: ..

(2007) The early anthropogenic hypothesis: ..

In 2003, Ruddiman developed his early anthropogenic hypothesis after examining 350,000 years of climate data from ice cores and other sources. He found that during interglacial periods, carbon dioxide and methane levels decreased, cooling the climate and making way for a succeeding glacial period. But, only during the Holocene era, these gas levels rose, coinciding, he said, with the beginning of large-scale agriculture. He attributed the rise to this human activity, which began occurring millennia before the industrial era.

Skeptic » eSkeptic » February 8, 2012

That idea, which came to be known as the “early anthropogenic hypothesis” was hotly debated for years by climate scientists, and is still considered debatable by some of these scientists. But in the new paper, Ruddiman and his 11 co-authors from institutions in the United States and Europe say that accumulating evidence in the past few years, particularly from ice-core records dating back to 800,000 years ago, show that an expected cooling period was halted after the advent of large-scale agriculture. Otherwise, they say, the Earth would have entered the early stages of a natural ice age, or glaciation period.

Climate Change Catastrophes in Critical Thinking

The 1970s Ice Age Myth and Time Magazine Covers ? by …

So NOW the NH gets mentioned. In any case, there was no significant change in global or any hemispheric temperature from the 1950s to the early 1970s. The last statistically significant cooling period ended in the 1950s.

04/06/2013 · This is a guest post by David Kirtley

Endless BS. OHC is calculated from thermometers that supposedly measured thousandths of a degree. It is the shortest and least reliable of T records. Surface T is the most difficult to compile–or replicate–or define. SST reflects the exact problems of OHC that you harp on, suggesting a one to one equivalence between land and sea is arbitrary and meaningless. Satellite measuring of the lower troposphere has the same advantages over ground stations as SAT measured SLR has over tide gauges. You have to be educated from scratch. –AGF

The 1970s Ice Age Myth and Time Magazine Covers – by David Kirtley

You’re just making shit up as usual. The industrial revolution was starting in a lot of countries in the early 1800s (even before 1800 in Great Britain). Also, there was zero trend in global temperature from 1850 to 1910, let alone anything statistically significant. So even with the early CO2 emissions to help, “coming out of the Little Ice Age” was producing ZERO global warming over that period.

Late Holocene climate: Natural or anthropogenic | …

During the 70’s it was learned from sediment and ice cores that interglacials were short and onsets of glaciation could be rapid, that we could be due for another big ice age. This recognition coincided with the last and coldest decade of a 30 year long cooling period, widespread tropical famine temperate crop failures. The cooling scare was as ill defined as the warming scare is now–a number of scenarios over disparate time frames could be meant. There was a solid consensus that we were due for another ice age eventually. The current interglacial had lasted already as long as the newly discovered average, and the LIA could well be taken as the new norm, with the warming up to the ’40s being anomalous. Armadillos were heading south, polar ice and glaciers and deserts were growing, crops were failing, food stores shrinking, and it was looking like climate could cause trouble. Nor Bryson nor any other expert ignored GHG heating, but it was obviously losing. Bryson blamed pollution: man was to blame. Most were skeptical, preferring to blame the sun or Milankovitch or whatever.

After 12 years of debate about whether the climate of the last several thousand years has been entirely natural or in considerable part the result of early agriculture, converging evidence from several scientific disciplines points to a major anthropogenic influence. – William Ruddiman

He attributed the rise in carbon dioxide emissions to the slash and burn techniques widely used by early farmers to make available large areas of land for crops. Ruddiman found that carbon dioxide levels rose beginning 7,000 years ago, and that methane began rising 5,000 years ago. He said this explains why a cooling trend didn’t happen that likely otherwise would have led to a new glacial period.

The Earth naturally cycles between cool glacial periods and warmer interglacial periods because of variations in its orbit around the sun. We currently are in an interglacial period, called the Holocene epoch, which began nearly 12,000 years ago.

Janvier, P., 1996, Early Vertebrates, Clarendon Press, Oxford

0330GMTC O’N: “Anyway, Imbrie stated a cooling trend from the Milankovitch cycles that started 6,000 years ago”Yet the LIA followed the MWP and was followed by early 20th century warming. So what do you think you’ve explained, you moron? Of such intellect are the doomsday cultists.